Electric lock actuator device

ABSTRACT

An electric lock actuator device (201), in particular for motor vehicles, comprising an electric motor (204) driving a recirculating ball worm screw unit (251, 260) for rectilinear movement of a cap element (264) slidable on a portion (207) of the frame (202) housing the motor (204) and adapted to act on a member (267) for locking and releasing the operation of a lock, and including a specific electronic control unit (27) for this electric motor (204), in which this electronic unit (27) includes a first integrated circuit (23) for distribution of electrical power supply for operation of the electric motor (204), and a second integrated circuit (25) for dealing with information signals relating to the operation of the motor (204), these integrated circuits (23, 25) being connected to a printed circuit (271) which is already utilised by slidable contact blades (270) having an end-of-stroke commutation function, fixed to the movement of this slidable cap (264), and which is housed in a portion (220) of the frame (202) of the device (201), which is integral with the portion (207) of the frame (202) housing the electric motor (204).

TECHNICAL FIELD

The present invention relates to an electric lock actuator device, andin particular to such a device of the type in which a DC electric motordrives, in a known way, by means of a recirculating ball worm screwunit, the rectilinear movement of an element displaceable with respectto the frame of the device, and a displacement actuator for a member forlocking and releasing the lock, conveniently this member can act torestrain or release a lock opening actuation lever which can be a doorlock, a boot lock or a fuel filler closure flap of a vehicle.

BACKGROUND ART

As is known, currently for the drive and control of such actuatordevices fitted on motor vehicles, use is made in practice of a wiringsystem dedicated to electrical supply for the motor, which leads from acommon central control unit for various actuator devices, which includerelay units, limiter circuits etc. This wiring system involves variousdisadvantages, including: the complexity and difficulty of fittingbundles of wires, the high number of electrical connections, thedifficulty of identification in the case of breakdowns, and thecomplexity of testing the operation of the system during and/or afterassembly on the vehicle.

From EP-A-77 254 and FR-A-2 600 366 electric lock actuator devices areknown, comprising an electric motor and a displacement actuator elementdisplaceable with respect to a frame of said device under the action ofsaid motor, for locking and releasing a lock in a vehicle, including aspecific electronic unit for controlling said electric motor, saidelectronic unit comprising a plurality of components connected to aprinted circuit and housed in a portion of said frame which is integralwith a portion of the frame housing said electric motor.

In said EP document, the frame has a substantially parallelepipedal flatshape, with the printed circuit housed parallel to the bigger bases ofthe frame and fixed thereto by virtue of screws. This arrangement isdisadvantageous since the resulting lock actuator is bulky and securingof the printed circuit requires additional operations involvingmanufacturing costs. In said FR document, on the contrary, no indicationis given on the exact arrangement of the printed circuit within theframe, whereas the electronic unit accommodated on the printed circuitonly comprises a pair of diodes.

DISCLOSURE OF THE INVENTION

The object of the present invention is to provide an actuator device ofthe general type disclosed in said EP and FR documents, designed toovercome the above drawbacks, i.e. which is very simple to produce andto assemble, has a small bulk and is also suitable for a drive andcontrol system of the type described in Italian Patent applicationentitled "A drive and control system for a plurality of electricaldevices in a vehicle" filed on th same date and corresponding toInternational Patent Application PCT/IT90/00023.

According to the present invention, there is provided an electric lockactuator device of the general type disclosed in said EP and FRdocuments, which is characterized in that said frame has a pair ofmutually facing grooves formed therein and in that said printed circuithas its lateral edges engaged within said facing grooves.

BRIEF DESCRIPTION OF DRAWINGS

For a better understanding of the present invention a particularembodiment thereof will now be described, by way of non-limitativeexample, with reference to the attached drawings, in which:

FIG. 1 is a partially sectioned side view of an electric lock actuatordevice formed according to the principles of the present invention; and

FIG. 2 is a partially sectioned front view of the actuator device ofFIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to FIG. 1, the reference numeral 201 generally indicatesan electric lock actuator device which includes, in a substantiallyknown way, a main frame 202 in the form of a shaped container,conveniently made of plastics material, having a substantially tubularmain portion 207 with flattened diametral sections which form aninternal through cavity 203 in a first section of which is housed a DCelectric motor 204 which has a drive spindle 250 which is secured bothangularly and axially to one end of a worm screw 251 which at its otherend axially contacts against a ball 252 which in turn is housed in acentral hub portion 253 which is supported by radial arm portions 254 atthe end of the tubular portion 207 opposite the housing zone of themotor 204. The other axial end of the motor 204, opposite the drivespindle 250 is engaged and centred on an external closure plug 216 ofthe cavity 203, which has a form similar to that of the tubular portion207, is conveniently made of plastics material, and is fixed at theextreme edge of the cavity 203 by cooperating coupling portions whichare conveniently snap-engageable.

On the screw 251 is engaged a nut 260 by means of a recirculating ballunit which is secured to a tubular body 261 housed slidably, but withoutthe possibility of rotating, within the cavity 203, and projects fromthis through the radial arm portions 254 with an end part 263 which isfixed within a tubular cap body 264 which is slidably disposed over apart, of corresponding section, of the tubular portion 207. This capbody 264 has at one end a pierced portion 266 in which a member 267,indicated in broken outline, can be connected in a known manner, whichis able to act for locking and release of a lock.

At the end of the tubular body 261, outside the cap body 264, there isfixed a pair of electrical blade contact elements 270 which are able toslide on respective tracks formed on the upper face of a printed circuitboard 271 which is housed in the cavity 203 beneath the motor 204, andengages with a terminal portion of a flattened portion 272 of thetubular portion 207. These electrical contact elements 270 are able toperform, in a known way, an electrical commutation function at the endof the displacement stroke of the tubular body 261 and therefore of thecap body 264.

The frame 202 further has two upper pierced portions 274 for connectionof the frame 202 itself to a convenient support.

According to the present invention, this frame 202 has, beneath a firstsection of the tubular portion 207, an integral portion 220 with twoparallel side walls 221, a base wall 222 and an end wall 223 which forma second cavity 225 underlying the cavity 203 and the longitudinal axisof which is parallel to the longitudinal axis of the cavity 203 itself.

Within this cavity 225 is housed an electronic unit 27 for control anddrive of the electric motor 204, according to the system described inthe said Italian Patent application entitled "Control and Drive Systemfor a Plurality of Electrical Devices in a Motor Vehicle". Inparticular, this unit 27 is connected to the already existing printedcircuit board 271 which is for this reason disposed with its lateraledges engaged within respective grooves 229 formed towards the upperzone of the side walls 221 (FIG. 2) where they join the tubular portion207.

To the lower face of the printed circuit 271 are connected:

three electrical contact elements 230, 231 and 232, conveniently of theblade type, which are housed in an insulating plug connector 233 whichis made integrally with the plug 216 for external closure of the cavity203, and shaped in such a way as to effect substantially sealed closureof the end opening of the cavity 225 opposite the end wall 223; thisconnector 233 is adapted to be coupled with a corresponding connectorblock 233' (illustrated in broken outline) connected to the end of anelectrical cable 235 having three electrical conductors the first ofwhich is a positive electrical power supply line, the second of which isan information signal transmission line, and the third of which is anearth connection line. This electrical cable 235 conveniently extendsfrom a main central control unit comprising a microprocessor to thisdevice 201 conveniently disposed in a vehicle door;

a first integrated circuit 23, provided with a dissipator 280 fordistribution of the electrical power supply to the motor 204 by means ofassociated electrical wires 236, and a second integrated circuit 25 forthe processing of information signals relating to the operation of thismotor 204. These integrated circuits 23 and 25 can conveniently includespecific logic circuits or a microprocessor, solid state switches etc,and can include excess current and excess voltage protection circuits,diagnostic and monitoring circuits etc, also in combination with otherdiscrete circuit components, all connected to the printed circuit 271.

INDUSTRIAL APPLICABILITY

The advantages obtained with the actuator device of the presentinvention are evident from what has been described in that, thanks tothe electronic unit 27, which makes it possible to process informationsignals relating to the operation of the device 201 itself and tocontrol the distribution of the electrical power supply for operation ofthe motor 205, significantly simplifies the assembly and reliability ofthe drive and control system by the significant reduction in the numberof connection wires as well as the associated connections; moreover thiselectronic unit 27 makes it possible to have a malfunction diagnosticfunction both for a greater safety in operation of the vehicle, in thatpossible anomalies can be indicated in good time to the driver, and fora reduction in repair times in that it can give the repair engineer anindication of the type of anomaly. All this translates obviously into asimplification of testing both in the assembly line and at the end ofthe assembly line. The provision of a specific electronic unit 27 forthis device 201 also makes it possible to vary the type of operation ofthe device itself, with the simple modification of the particularelectronic unit and the programme resident in the central unit. Thehousing of this electronic unit 27 is further achieved in an economicmanner with a simple modification of the conventional frame, by theintegral portion 220 which does not substantially alter the mostcritical dimensions of the device 201 which, therefore, can still behoused in the door in the usual position. Such a frame 202 couldtherefore also be provided for devices 201 whether or not they have theelectronic unit 27. The connector unit 233, as well as being integralwith the conventional plug 216, further constitutes the closure andprotection element for the electronic unit 27.

We claim:
 1. An electric lock actuator device (201) comprising anelectric motor (204) and a displacement actuator element (264)displaceable with respect to a frame (202) of said device under theaction of said motor (204), for locking and releasing a lock in avehicle, including a specific electronic unit (27) for controlling saidelectric motor (204), said electronic unit (27) comprising a pluralityof components (23, 25) connected to a printed circuit (271) and housedin a portion (220) of said frame (202) which is integral with a portion(207) of the frame (202) housing said electric motor (204),characterized in that said frame (202) has a pair of mutually facinggrooves (229) formed therein and in that said printed circuit (271) hasits lateral edges engaged within said facing grooves (229); wherein saidportion (220) of the frame (202) housing said electronic unit (27) islaterally adjacent to said portion (207) of the frame housing saidelectric motor (204) and is separated therefrom by said printed circuit(271); and wherein said printed circuit (271) has a first face lookingtoward said portion (207) housing said electric motor (204), said firstface carrying means (270) to determine variation of at least oneelectrical signal in dependence on at least one limit position of saiddisplacement actuator element (264), and a second opposite face lookingtoward said portion (220) housing said electronic unit (27), said secondopposite face carrying said components (23, 25).
 2. A device accordingto claim 1, characterized in that said portions (220, 207) of the frame(202) housing said electronic unit (27) and said motor (204) definemutually parallel, main longitudinal axes, said grooves (229) extendingparallel to said main longitudinal axes in opposite side walls (221) ofsaid frame (202).
 3. A device according to claim 1, characterized inthat said means operable to determine variation of at least oneelectrical signal comprises at least one electrical contact element(270) slidable on said first face of said printed circuit (271) andsecured to a portion (261) fixed to said displacement actuator element(264).
 4. A device according to any one of claims 1 or 2, characterizedby a closure cap (216) closing said portion (207) of the frame (202)housing said electric motor (204), said closure cap (216) being integralwith a three element connector (233) externally closing said portion(220) of the frame (202) housing said electronic unit (27), saidconnector (233) including a first power level positive electrical supplylead, a second information signal transmission lead and a third earthconnection lead for connection to an electrical connection cable (235).5. A device according to any one of claims 1 or 2, characterized in thatsaid displacement actuator element (264) for locking and releasing saidlock is slidable along said frame (202) housing said motor (204) and issecured to a body (261) displaceable under the action of said motor(204) via a recirculating ball worm screw unit (251, 260).
 6. A deviceaccording to any one of claims 1 or 2, characterized in that saidelectronic unit (27) includes at least one first integrated circuit (23)for distribution of the electrical power supply for operation of saidelectric motor (204), and at least a second integrated circuit (25) fordealing with information signals relating to the operation of said motor(204).
 7. A device according to any one of claims 1 or 2, characterizedin that said specific electronic control unit (27) includes diagnosticand/or indication means for possible breakdowns of said device (201). 8.A device according to any one of claims 1 or 2, characterized in that itis applied to a vehicle door lock.
 9. An electric lock actuator device(201) comprising an electric motor (204) and a displacement actuatorelement (264) displaceable with respect to a frame (202) of said deviceunder the action of said motor (204), for locking and releasing a lockin a vehicle, including a specific electronic unit (27) for controllingsaid electric motor (204), said electronic unit (27) comprising aplurality of components (23, 25) connected to a printed circuit (271)and housed in a portion (220) of said frame (202) which is integral witha portion (207) of the frame (202) housing said electric motor (204),characterized in that said frame (202) has a pair of mutually facinggrooves (220) formed therein and in that said printed circuit (271) hasits lateral edges engaged within said facing grooves (229); comprising aclosure cap (216) closing said portion (207) of the frame (202) housingsaid electric motor (204), said closure cap (216) being integral with athree element connector (233) externally closing said portion (220) ofthe frame (202) housing said electronic unit (27), said connector (233)including a first power level positive electrical supply lead, a secondinformation signal transmission lead and a third ground connection leadfor connection to an electrical connection cable (235).
 10. A deviceaccording to claim 9, wherein said portion (220) of the frame (202)housing said electronic unit (27) is laterally adjacent to said portion(207) of the frame housing said electric motor (204) and is separatedtherefrom by said printed circuit (271).
 11. A device according to claim9, wherein said portions (220) of the frame (202, 207) housing saidelectronic unit (27) and said motor (204) define mutually parallel, mainlongitudinal axes, said grooves (229) extending parallel to said mainlongitudinal axes in opposite side walls (221) of said frame (202).